How to add detailed engravings onto a curved surface in Blender for 3D-printing?
You could try and model it with Bezier Curve objects combined with a Shrink Wrap modifier.
Just model use a any bezier curve object, define any desired section and use it as bevel object.

Apply a Shrink Wrap modifier to the curve, but the important part is to activate the option Apply this and all preceding deformation modifiers on splines’ points rather than on filled curve/surface.

This will make it so the bezier control points are wrapped to the surface, rather than the final beveled geometry, so that the curve can be beveled live, but its thickness and shape is kept.

Then adjust and model as desired, you can use curve radius to make certain parts thicker or thinner.